Muzzle attachment system

ABSTRACT

A muzzle attachment system for a firearm includes a muzzle attachment having a first engagement means, and a muzzle distal portion including a second engagement means, the second engagement means being complementary with the first engagement means. The first and second engagement means cooperate to releasably secure the muzzle attachment to the muzzle distal portion. The first and second engagement means preferably include complementary coarse threaded engagement portions, an annular grooved surface having a plurality of grooves, a grooved surface engagement mechanism, and first and second position stops that abut to form a gas seal. The muzzle distal portion is preferably a flash suppressor, including at least two elongated ports substantially equally skewed from normal relative to a firing axis of the firearm, and substantially evenly distributed around the circumference of the flash suppressor.

This application claims the benefit of Provisional Application No.60/764,166, filed Jan. 31, 2006, the contents of which are hereinincorporated by reference in their entirety.

BACKGROUND

A variety of devices have been developed for use in connection with themuzzle of a firearm. These devices, or muzzle attachments, includesilencers, rocket and/or grenade launchers, line launchers, and thelike. Because the circumstances under which a firearm is being used areliable to change quickly, it is desirable that the muzzle attachmentsand/or the corresponding firearm be adapted to allow rapid and reliablesecuring and removal of the muzzle attachments.

The reliability of the connection of the muzzle attachment and muzzle,and the ease or quickness with which the muzzle attachment is securedand removed, tend to provide competing objectives in the design of amuzzle attachment system. For example, large numbers of fine threads andlocking pins typically provide a very reliable connection but require arelatively long amount of time to secure or remove. The use of one ormore tools may also be required.

In addition to providing a sufficiently secure, yet readily releasableconnection, for many types of muzzle attachments it is also importantthat a muzzle attachment system ensure proper alignment of the muzzleattachment relative to the barrel and firing axis of the firearm. Forinstance, some muzzle attachments, such as silencers, substantiallyencircle the firing axis, and the projectile, once exiting the muzzle,must also pass through the muzzle attachment.

Many existing firearms are manufactured with a muzzle that includes adistal portion having a flash suppressor and/or compensator. Flashsuppressors are designed to reduce the visible flash produced by hotgases exiting the muzzle, thereby reducing the deleterious effect such aflash would otherwise have on the night vision of the user, when thefirearm is used in darkness. The muzzle flash is produced by the rapidignition of un-burnt gunpowder leaving the muzzle after the projectile,together with the high velocity and temperature gases.

Flash suppression effects are typically achieved by both graduallyincreasing the diameter of an inner surface the distal portion, whichinner surface is concentric with the firing axis, and providing one ormore ports, elongated in the direction of the firing axis, around thecircumference of the distal portion, which ports extend between an outersurface, also concentric with the firing axis, and the inner surface ina generally radial direction. As the projectile exits the muzzle throughthe inner surface of the distal portion, the hot gases trailing theprojectile expand radially outward through the ports. The resultantlower temperature and velocity of the gases result in a less violentcombustion of the remaining gunpowder, and a correspondingly lessintense flash. While many flash suppressor designs feature ports thatextend outward normal to the firing axis, more effective flashsuppression is generally achieved by having one or more ports thatextend outward less than normal, in a skewed geometry.

Compensators, generally, compensate for, or mitigate one or moreundesirable motions of the firearm that occur as a result of firing.Such undesirable motions include recoil and muzzle lift. A flashsuppressor arrangement is typically designed to also compensate for oneor both of these undesirable motions. For instance, vectoring the highvelocity gases radially away from the firing axis for flash suppressionpurposes also tends to mitigate the recoil that would be caused by suchgases exiting the muzzle along the firing axis. By eliminating portsfrom a bottom side of the circumference of the distal portion, the forceexerted by the radially dissipated gases exiting the ports arranged onan upper side of the circumference of the distal portion tends tocounteract muzzle lift.

Because the distal portion, typically a flash suppressor, is usuallydesigned and manufactured to be removable, many muzzle attachment systemdesigns involve replacing the stock distal portion with a modifieddistal portion. The modified distal portion is adapted for releasableconnection with a complementarily adapted muzzle attachment. Typically,the modified distal portion is intended to remain in place on thefirearm, even when no muzzle attachment is connected. Accordingly, themodified distal portion is frequently also designed to serve as flashsuppressor and compensator.

Some types of muzzle attachments, such as silencers and other can- orcanister-type attachments, must substantially enclose the modifieddistal portion. Any adverse effect this enclosure would have on theflash suppression or compensation effects of the modified distal portionis typically mitigated, as the muzzle attachment itself may providesubstantial flash suppression and/or compensation, ancillary to themuzzle attachment's primary purpose. For instance, silencers tend toeffectively suppress muzzle flash and provide some compensation,ancillary to their primary purposes of muffling the audible report ofthe firearm.

However, the fact of this enclosure by certain muzzle attachments hastended to influence the design of the modified distal portion.Particularly, until the present invention, modified distal portionsincluding ports skewed from normal, relative to the firing axis, havenot been employed, as the inclusion of such ports in conventionalconfigurations tends to impart undesirable torsional forces to themuzzle attachment, when connected. Accordingly, firearms employing priorart muzzle attachment systems with modified distal portions exhibitinferior flash suppression capabilities when no muzzle attachment isconnected.

Some of the unburnt powder, as well as other particulate matterentrained in the expanding hot gases behind the bullet or projectile,tends to deposit both along the barrel of the rifle and within thedistal portion and the muzzle attachment. As a result, periodic cleaningof the firearm, including the distal portion and muzzle attachment, isrequired to remove these deposits. If the interface between thecorresponding engagement surfaces on the muzzle attachment and themodified distal portion is not sufficiently isolated from the expandinggases to prevent deposition of particulate matter on the engagementportions, deposits on the engagement surfaces can result in binding ofthe muzzle attachment to the distal portion, as well as damage to theengagement portions. Damage to the engagement portions can result in anundesirable discharge of gases between the muzzle attachment and themodified distal portion, leading to decreased efficacy of the muzzleattachment and impaired accuracy.

From the foregoing, it can be seen that there is a need for a muzzleattachment system that provides for both a connection between thefirearm and the muzzle attachment that is reliable and secure, but whichalso allows for the muzzle attachment to be easily and quickly connectedand disconnected. There is also a need for a muzzle attachment systemhaving a modified distal portion incorporating skewed ports for enhancedflash suppression when no muzzle attachment is in place while avoidingundesirable torsional forces when a muzzle attachment surrounding theskewed ports is connected. Additionally, there is a need for a muzzleattachment system in which the engagement portions are not exposed toparticulate deposition from the expanding gases.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a muzzle attachmentsystem for a firearm includes a muzzle attachment having a firstengagement means, and a muzzle distal portion including a secondengagement means, the second engagement means being complementary withthe first engagement means. The first and second engagement meanscooperate to releasably secure the muzzle attachment to the muzzledistal portion.

According to one aspect of the present invention the first and secondengagement means include complementary coarse threaded engagementportions. The coarse threaded engagement portions allow for quick andeasy attachment and detachment. The first engagement means and secondengagement means also include an annular grooved surface having aplurality of grooves, and a grooved surface engagement mechanism.

The annular grooved surface and the grooved surface engagement mechanismengage one another with sufficient force to overcome torsional forcesacting on the muzzle attachment during use, even when the muzzleattachment is not completely screwed on to the muzzle distal portion.However, the force exerted between the annular grooved surface and thegrooved surface engagement mechanism still permits easy manual removalof the muzzle attachment.

According to another aspect of the present invention the first andsecond engagement portions include first and second position stops thatprevent overtightening of the coarse threaded portions and abut to forma gas seal, the gas seal substantially preventing gases exiting themuzzle distal portion from reaching the coarse threaded portions,thereby preventing fouling.

According to a further aspect of the present invention, the muzzledistal portion is a flash suppressor, the flash suppressor including atleast two elongated ports substantially equally skewed from normalrelative to a firing axis of the firearm, the at least two elongatedports being substantially evenly distributed around the circumference ofthe flash suppressor. Thus, the flash suppression of the distal portionis enhanced when no muzzle attachment is in place.

These and other features and advantages of the present invention will bebetter understood in view of the drawings and the detailed description,below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a silencer and a flash suppressor employing a muzzleattachment system, according to an embodiment of the present invention;

FIG. 2 shows a side view of the flash suppressor of FIG. 1;

FIG. 3 shows a side view of the silencer of FIG. 1;

FIG. 4 shows an end view of the silencer of FIG. 3;

FIG. 5 shows a sectional view of the flash suppressor of FIG. 2, withanother notch embodiment;

FIG. 6 shows a side view of the flash suppressor of FIG. 2, with thenotch embodiment of FIG. 5, and with the grooved surface engagementmechanism removed;

FIG. 7 shows a sectional view of the flash suppressor of FIG. 6, takenalong line 7-7;

FIG. 8 shows a sectional view of the flash suppressor of FIG. 6, takenalong line 8-8; and

FIG. 9 shows a side view of the flash suppressor of FIG. 2, with anexploded view of the grooved surface engagement mechanism.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to FIG. 1, a muzzle attachment system 10 according to anembodiment of the present invention, includes a silencer 12, also knownas a sound suppressor, and a flash suppressor 14. Referring to FIGS. 3and 4, the silencer 12 has a cylindrical body 20, partially defining aninterior volume 22, which interior volume 22 concentrically surrounds afiring axis 24 of a firearm (not shown). The cylindrical body 20 extendsbetween a first end 26 and a second end 28, the first and second ends26, 28 each disposed substantially perpendicularly to the firing axis24.

In the vicinity of the first end 26, proximate to a muzzle (not shown)of the firearm when the silencer 12 is connected to the firearm, aninternal passage 30 is defined within the cylindrical body 20. Theinternal passage 30 extends between a first passage opening 32 in thefirst end 26 and a second passage opening 34, the second passage opening34 communicating with the internal volume 22. The internal passage 30,first passage opening 32 and second passage opening 34 are eachsubstantially concentric to the firing axis 24.

The silencer 12 is further formed with first engagement means 38,including a female coarse-threaded portion 40 and a first position stop42, in the internal passage 30, and an annular grooved surface 44 (bestseen in FIG. 4), including a plurality of grooves 46, extending radiallyoutward relative to the firing axis 24. The annular grooved surface 44is formed on the first end 26, surrounding the first passage opening 32.A projectile discharge opening is disposed in the second end 28 and alsoarranged substantially concentrically with the firing axis 24.

Referring to FIGS. 2, 5 and 6, the flash suppressor 14 is formed as agenerally cylindrical body 50 concentric to the firing axis 24, andhaving a first end 52 and a second end 54, the first and second ends 52,54 disposed substantially perpendicular to the firing axis 24. A muzzleengagement portion 56 extends into the cylindrical body 50 from thefirst end 52 and is designed to engage the muzzle end of the firearmbarrel (not shown) when a stock distal portion (not shown) is removed.

A frustoconical cavity 58, concentric to the firing axis 24, extendsinto the cylindrical body 50 from the second end 54. Communicationbetween the firearm barrel, when engaged in the muzzle engagementportion and the frustoconical cavity 58 is through a small bore 60 and alarge bore 62, both bores 60, 62 concentric to the firing axis 24. Thefrustoconical cavity 58, together with the large bore 62, partiallydefine a gas expansion volume 64.

Each of a plurality of elongated ports 70 extend through the cylindricalbody 50 to the gas expansion volume 64. The elongated ports 70 areevenly spaced around the cylindrical body 50, and as can best be seen inFIG. 7, each of the elongated ports 70 is equally skewed from normal 72relative to the firing axis 24.

One or more notches 74 are formed in the cylindrical body 50 proximateto the second end 54. Notches 74 a, 74 b show different notchembodiments, notches 74 a (FIGS. 2 and 9) having a triangular profileand notches 74 b (FIGS. 5 and 6) an overlapping semi-circular profile.Typically, the flash suppressor 14 is provided with two notches 74,having the same profile, on opposing sides of the cylindrical body 50.When the muzzle attachment, such as silencer 12 is not in place, notches74 facilitate proper alignment of the firearm when shooting through theshank of a padlock, a wire, or the like, and result in a more aggressiveappearance of the firearm. Alternately, notches 74 can be omitted.

Opposing flat surfaces 76, best seen in FIG. 8, are formed in thecylindrical body 50 proximate to the first end 52 to allow a wrench, orthe like, to be used for tightening the flash suppressor 14 onto thefirearm muzzle when replacing the stock distal portion (not shown) withthe flash suppressor 14. Adjacent to the flat surfaces 76 an annulargroove 78 is formed in the cylindrical body 50.

The flash suppressor 14 is further formed with second engagement means80, complementary to the first engagement means 38. The secondengagement means 80 include a second position stop 82, a malecoarse-threaded portion 84, and a grooved surface engagement mechanism86. The grooved surface engagement mechanism 86 (best seen in FIG. 9)includes a retaining ring 88, dimensioned to snap-fit into the annulargroove 78, a biasing means 90, such as a wave spring, and atoothed-washer 92. The toothed-washer 92 is formed with a plurality ofteeth 94. Each tooth 94 is dimensioned to complementarily engage acorresponding one of the plurality of grooves 46.

An accommodating portion 96 of the cylindrical body 50 accommodates thewave spring 90 and the toothed-washer 92 between the retaining ring 88,in the annular groove 78, and the male coarse-threaded portion 84.Preferably, the diameter of at least a portion of the cylindrical body50 in the area of the male coarse-threaded portion 84 slightly exceedsthe diameter of the accommodating portion 96, so as to limit the motionof the toothed-washer 92 along the cylindrical body 50 in the directionof the male coarse-threaded portion 84.

Referring again to FIG. 1, when the muzzle attachment system 10 is fullyconnected, the first position stop 42 (FIG. 3) and the second positionstop 82 (FIG. 5) abut, thereby cooperating to form a gas seal 100. Hotgases expanding in the internal volume 22 toward the second passageopening 34 are, thus, impeded from reaching the female and male coarsethreaded portions 40, 84 and potentially harmful deposits thereon aresubstantially prevented.

In operation, the stock distal portion (not shown) is removed from thefirearm muzzle (not shown). The grooved surface engagement mechanism 86is positioned around the cylindrical body 50 of the flash suppressor 14,such that the retaining ring 88 is snap-fit into the annular groove 78to retain the wave spring 90 and the toothed-washer 92 around theaccommodating portion 96. With the grooved surface engagement mechanism86 in place, the muzzle engagement portion 56 of the flash suppressor 14is secured to the firearm muzzle and tightened using a wrench (notshown), or the like on the flat surfaces 76. The firearm is thenoperable for normal use without any muzzle attachment.

To attach the silencer 12 to the flash suppressor 14, the second end 54of the flash suppressor 14 cylindrical body 50 is partially insertedthrough the internal passage 30 of the silencer 12, until the malecoarse-threaded portion 84 abuts the female coarse-threaded portion 40.The silencer 12 is then rotated about the firing axis 24 to inter-engagethe male and female coarse-threaded portions 84, 40.

Rotating the silencer 12 brings the annular grooved surface 44 intoengagement with the toothed-washer 92 of the grooved surface engagementmechanism 86, and compresses the wave spring 90 between the retainingring 88 and the toothed-washer 92. Wave spring 90 biases thetoothed-washer 92 against the annular grooved surface 44, with eachtooth 94 being held in engagement with a corresponding groove 46.

The rotation of silencer 12 continues until the first position stop 42abuts the second position stop 82. The abutment of the first and secondposition stops 42, 82 provides a user with a clear indication that thesilencer 12 attachment is complete and prevents over-tightening of thesilencer 12, thus avoiding possible damaging of the coarse-threadedportions 84, 40 and/or complicating subsequent removal of the silencer12.

It will be appreciated from the above-description that the use ofcoarse-threaded portions 84, 40 allows for quick and easy removal andattachment of the silencer 12, or other muzzle attachment. The groovedsurface engagement mechanism 86 produces sufficient force to overcomeany torsional forces acting on the silencer 12 during operation thefirearm with the silencer 12 in place, while requiring minimal force tomanually overcome the engagement and remove the silencer 12.

It will be clear to those skilled in the art that the present inventionis not limited to the embodiments described, but that numerousvariations and modifications are possible within the scope of thepresent invention.

Although the present invention has been described with reference to thesilencer 12, it will be appreciated by those skilled in the art that themuzzle attachment system of the present invention is equally adaptableto any of a variety of other common muzzle attachments, such as thoselisted above, without departing from the scope of the invention.Additionally, although the present invention references a combination ofa distal portion and a muzzle attachment, both muzzle distal portionsand muzzle attachments separately fall within the scope of the presentinvention, if the muzzle distal portions and/or the muzzle attachmentare adapted for use with the muzzle attachment system of the presentinvention.

The modified distal portion used in the muzzle attachment system of thepresent invention is shown as the flash suppressor 14. It will beappreciated that, within the scope of the present invention, modifieddistal portions with other features and capabilities are advantageouslyemployable, and that the distal portion need not include a flashsuppressor. Additionally, though the present invention is described inconnection with a modified distal portion that replaces a stock distalportion, stock distal portions can also be advantageously modifiedaccording to the muzzle attachment system of the present invention,whether or not such stock distal portions are replaceable. Where areplacement modified distal portion is used, the present invention isnot limited to any particular means for attaching the modified distalportion to the distal end of the firearm barrel. One advantageous meansincludes fine threads on the distal end of the firearm barrel and in themuzzle engagement portion 56.

Although the flash suppressor 14 preferably includes skewed elongatedports 70, and flash suppressor that includes elongated ports that extendthrough the cylindrical body 50 in a direction normal 72 from the firingaxis, is also within the scope of the present invention. However, theinventors of the present invention have found that the flash suppressor14 with skewed elongated ports 70 is advantageously employable with themuzzle attachment system 10, while avoiding the undesirable torsionalforces discussed above, if the elongated ports 70 are evenly distributedaround the circumference of cylindrical body 50 and if each port isskewed to the same degree. Thus, the flash suppressor 14 enablesenhanced flash suppression, relative to non-skewed ports extendingnormal to the firing axis, when no muzzle attachment, such as silencer12, is in place. The present inventors have further found that a flashsuppressor 14 with four elongated ports results in extremelysatisfactory performance.

Although the wave spring 90 is shown as the biasing means 90, it willalso be appreciated that other biasing means 90 can be used in additionto, or in place of the wave spring 90. Although the retaining ring 88 isshown as snap-fitted into the annular groove 78, other placement meansfor ensuring the positioning the biasing means and the toothed-washerare possible within the scope of the present invention.

While the use of four evenly distributed teeth 94 on the toothed-washer92 has been found optimal for evenly distributing the contact of thetoothed-washer 92 with the annular grooved surface 44 and ensuringproper alignment of the silencer 12 relative to the firing axis 24, moreor less teeth 94 can be used, although at least two teeth 94 arepreferred, and it is further preferred that the teeth 94 be evenlydistributed on the toothed-washer 92. The teeth 94 can also be placed onthe silencer 12 and the annular grooved surface 44 on the washer 92.Additionally, other complementary shapes for teeth 94 and grooves 46fall within the scope of the present invention. For instance, knurlingor complementary hemispherical cavities and protrusions may also beemployed.

These and other modifications, variations, and adaptations forparticular circumstances are all possible within the scope of thepresent invention.

1. A muzzle attachment system for a firearm, the attachment systemcomprising: a tool-less muzzle attachment having a female coarsethreaded engagement means, and one of an annular grooved surface and agrooved surface engagement mechanism formed on an end of the muzzleattachment; and a muzzle distal portion having a male coarse threadedengagement means complementary with the female coarse threadedengagement means, and the other of the annular grooved surface and thegrooved surface engagement mechanism; wherein the male and female coarsethreaded engagement means include a single set of complementary gassealing surfaces, said complementary gas sealing surfaces being taperedand positioned on respective distal ends of the male and female coarsethreaded engagements means; wherein the male and female coarse threadedengagements means cooperate to releasably secure the muzzle attachmentto the muzzle distal portion; wherein said male and female coarsethreaded engagement means have approximately four or less threads suchthat approximately four or fewer rotations of said muzzle attachment arerequired to secure said muzzle attachment to said muzzle distal portionand to establish a single gas seal; and wherein the annular groovedsurface has a plurality of grooves extending radially outward relativeto a firing axis of the firearm.
 2. (canceled)
 3. The muzzle attachmentsystem of claim 1, wherein the male and female coarse threadedengagement means include, respectively, a first and a second positionstop, the first and second position stops engaging prior toover-tightening of the female and male coarse threaded portions, therebypreventing over-tightening.
 4. The muzzle attachment system of claim 3,wherein said first and second position stops are the gas sealingsurfaces that abut to form a gas seal, the gas seal substantiallypreventing gases exiting the muzzle distal portion from reaching thefemale and male coarse threaded portions.
 5. The muzzle attachmentsystem of claim 1, wherein the muzzle distal portion is a flashsuppressor, the flash suppressor including at least two elongated portssubstantially equally skewed from normal relative to a firing axis ofthe firearm, the at least two elongated ports being substantially evenlydistributed around the circumference of the flash suppressor.
 6. Themuzzle attachment system of claim 5, wherein the flash suppressorincludes four elongated ports substantially equally skewed from normalrelative to a firing axis of the firearm, the four ports beingsubstantially evenly distributed around the circumference of the flashsuppressor.
 7. (canceled)
 8. The muzzle attachment system of claim 1,wherein the annular grooved surface is formed on an end of the muzzleattachment substantially perpendicular to a firing axis of the firearmand the muzzle distal portion carries the grooved surface engagementmechanism.
 9. The muzzle attachment system of claim 8, wherein thegrooved surface engagement mechanism includes a toothed-washer having atleast one tooth, the at least one tooth being complementary with any ofthe plurality of grooves.
 10. The muzzle attachment system of claim 9,wherein the toothed-washer includes at least two teeth substantiallyevenly distributed on the toothed-washer.
 11. The muzzle attachmentsystem of claim 10, wherein the toothed-washer includes four teethsubstantially evenly distributed on the toothed-washer.
 12. The muzzleattachment system of claim 9, wherein the grooved surface engagementmechanism further includes a biasing means for biasing thetoothed-washer toward the annular grooved surface.
 13. The muzzleattachment system of claim 12, wherein the biasing means includes a wavespring.
 14. The muzzle attachment system of claim 12, wherein thegrooved surface engagement mechanism further includes a retaining ringfor retaining the biasing means and the toothed-washer in positionaround the muzzle distal portion.
 15. The muzzle attachment system ofclaim 14, wherein an annular groove is formed around the circumferenceof the muzzle distal portion, and the retaining ring snap-fits into theannular groove.
 16. A muzzle distal portion for use in a muzzleattachment system, the muzzle distal portion comprising: a male coarsethreaded engagement means for engagement with a tool-less muzzleattachment; one of an annular grooved surface having a plurality ofradially extending grooves and a grooved surface engagement mechanismfor engaging a complimentary other of the annular grooved surface andthe grooved surface engagement mechanism on the muzzle attachment; and asingle gas sealing surface configured to sealingly contact the muzzleattachment; wherein said gas sealing surface is tapered and positionedon a distal side of the male coarse threaded engagement means; andwherein said male coarse threaded engagement means includesapproximately four or less threads such that approximately four or fewerrotations of said muzzle attachment are required to secure said muzzleattachment to said muzzle distal portion to establish a single gas seal.17. (canceled)
 18. The muzzle distal portion of claim 16, wherein thegrooved surface engagement mechanism includes a toothed-washer having atleast one tooth, the at least one tooth being complementary with any ofa plurality of grooves in the complementary annular grooved surface. 19.The muzzle distal portion of claim 18, wherein the grooved surfaceengagement mechanism further includes a biasing means for biasing thetoothed-washer toward the annular grooved surface.
 20. The muzzle distalportion of claim 19, wherein the grooved surface engagement mechanismfurther includes a retaining ring for retaining the biasing means andthe toothed-washer in position around the muzzle distal portion. 21.(canceled)
 22. The muzzle distal portion of claim 16, wherein the muzzledistal portion has an accommodating portion, the toothed-washer and thebiasing means being arranged around the accommodating portion, and themale coarse threaded portion has a diameter larger than a diameter ofthe accommodating portion, such that the toothed-washer and the biasingmeans are retained between the retaining ring and the male coarsethreaded portion.
 23. The muzzle distal portion of claim 16, wherein theengagement means includes a position stop for engaging a complementaryposition stop on the muzzle attachment, the position stop on the muzzledistal portion adapted to form a gas seal when abutting thecomplementary position stop on the muzzle attachment.
 24. The muzzledistal portion of claim 16, wherein the muzzle distal portion is a flashsuppressor, the flash suppressor including at least two elongated portssubstantially equally skewed from normal relative to a firing axis ofthe firearm, the at least two elongated ports being substantially evenlydistributed around the circumference of the flash suppressor.
 25. Themuzzle distal portion of claim 24, wherein the flash suppressor includesfour elongated ports substantially equally skewed from normal relativeto a firing axis of the firearm, the four ports being substantiallyevenly distributed around the circumference of the flash suppressor. 26.A tool-less muzzle attachment for use in a muzzle attachment system, themuzzle attachment comprising: a female coarse threaded engagement meansfor engagement with a muzzle distal portion; one of an annular groovedsurface having a plurality of radially extending grooves and a groovedsurface engagement mechanism for engaging a complimentary other of theannular grooved surface and the grooved surface engagement mechanism onthe muzzle distal portion; and a single gas sealing surface configuredto sealingly contact the muzzle distal portion; wherein said gas sealingsurface is tapered and is positioned on a distal side of the femalecoarse threaded engagement means; and wherein said female coarsethreaded engagement includes approximately four or less threads suchthat approximately four or fewer rotations of said muzzle attachment arerequired to secure said muzzle attachment to said muzzle distal portionto establish a gas seal.
 27. The muzzle attachment of claim 26, whereinthe engagement means includes an annular grooved surface on the muzzleattachment for engaging a complementary grooved surface engagementmechanism on the muzzle distal portion.
 28. The muzzle attachment ofclaim 27, wherein the annular grooved surface is arranged to besubstantially perpendicular to a firing axis of a firearm when attachedto the muzzle distal portion.
 29. The muzzle attachment of claim 26,wherein the engagement means includes a position stop for engaging acomplementary position stop on the muzzle attachment, and wherein theposition stop on the muzzle attachment is the gas sealing surfaceadapted to form a gas seal when abutting the complementary position stopon the muzzle distal portion.
 30. The muzzle attachment of claim 29,wherein the muzzle attachment at least partially defines an interiorvolume and the position stop is arranged between the interior volume andthe female coarse threaded engagement means.